A young male patient with rapidly progressive and life-threatening pulmonary haemorrhage due to anti-glomerular basement membrane (anti-GBM) antibody disease without renal involvement repeatedly tested negative for serum anti-GBM antibodies. Although rare, anti-GBM antibody disease should be considered in the differential diagnosis in patients with life-threatening pulmonary haemorrhage due to isolated diffuse alveolar haemorrhage. Enzyme-linked-immunosorbent assay (ELISA) testing for anti-GBM antibodies in anti-GBM antibody disease can give false-negative results. A negative serum anti-GBM antibody test is therefore insufficient to exclude the diagnosis. Thus, a kidney or lung biopsy should be considered in any case with a high clinical suspicion but negative anti-GBM antibody test to confirm or rule out the diagnosis.
Learning points: Diffuse alveolar haemorrhage (DAH) is a life-threatening disorder caused by severe damage due to injury or inflammation of the alveolar-capillary basement membrane.Anti-GBM antibody disease is a rare autoimmune disorder with circulating autoantibodies directed against the alpha-3 chain[Q2] of type VI collagen of the glomerular and/or alveolar basement membrane which may result in oliguric acute kidney failure due to rapidly progressive glomerulonephritis with or without DAH (commonly referred to as Goodpasture's syndrome).A kidney or lung biopsy should be considered to confirm or rule out the diagnosis if there is a high clinical suspicion but the anti-GBM antibody test is negative; prompt diagnosis and initiation of plasmapheresis, cyclophosphamide and prednisone therapy is essential.
Keywords: Goodpasture; anti-GBM antibodies; diffuse alveolar hemorrhage.